Skyrim is an all consuming game, though it has no multiplayer at all, and never will. Uncontested game of the year in my opinion.
Uncharted is a good franchise, and 2 and 3 both have critically acclaimed multiplayer (I have played 1 and 2, great games, though I didn't touch the multiplayer)
Warhammer 40,000: Space Marine was fun for me, and the multiplayer was decent, I have not tried the new co-op mode. I'm a huge fan of the universe the game exists in, its not for everyone.
Dark Souls is a great game, and definitely not for everyone. It is very hard. You will die, alot. Its got a unique multiplayer, no voice chat or communicating with anything other than gestures. There is a co-op where you work with up to 2 other players to defeat bosses. Or you do pvp on an 'invasion.' You will die alot. And the game offers no helping hands, either find a wiki or dive in. Not for everyone, but I loved it. Did I mention you will die alot?
Dead Island is a fun game, some frame rate issues, and a somewhat dated look in some places. It does have online co-op.
Deus Ex: Human Revolution is another good fps/rpg hybrid, a lot of fun and quite a bit of freedom.
I can offer deeper opinions or info on any of these if that helps.